Members of the demining unit of Hezbollah raise their hands as they shout slogans in support of pro-Hezbollah leader Sheik Hassan Nasrallah Saturday.

The European Union is poised to add the military wing of Lebanese Hezbollah to its list of banned terrorist groups. Why not the whole organization?

Let's start by saying that it will be good news if the U.K. can persuade the other 26 EU countries to list even part of Hezbollah as a terrorist outfit. Europe has held off for far too long - even after the Bulgarian government connected Hezbollah to a bus bombing last July that killed five Israeli tourists and their driver. The designation would make it much harder for the group to finance its operations through Europe and its banks, or for European officials to talk openly with it.

An EU working group is scheduled to meet next week to discuss the listing and will make a recommendation to the wider organization. France and Germany have both swung behind the U.K. proposal on the partial listing, making it likely to pass. So far, though, the Netherlands is the only European government to list the whole of Hezbollah as a terrorist group, something Israel did in 1989 and the U.S. in 1997.

Although it seems absurd to make a distinction between the "bad" and "not quite so bad" divisions of the same organization, it can be exactly the right thing to do. "We never talk to terrorists" is a popular line for governments to take, but also a dumb one. U.K. negotiations with Sinn Fein, the political arm of the Irish Republican Army, helped make a peace agreement possible.

Yet such selective distinctions only work in very particular circumstances. You need a good reason to keep up the fiction that a movement's political leaders aren't connected to its terrorist operations (not even Hezbollah claims they are separate), because there are costs involved in trying to split the difference. So long as one part of the organization can recruit and raise money legally, it can support its military operations, and Hezbollah has an extensive financial network in Europe.

Most European leaders clearly think it is worth the cost to make the political-military distinction in Hezbollah's case. Until last year, the group hadn't carried out a terrorist attack in Europe since the 1990s. It was also an important part of Lebanon's elected government, representing Shiites in the country's delicate sectarian balance. U.K. officials say they are reluctant to condemn Hezbollah as a movement, because it would be destabilizing for Lebanon. France took the same position.

That argument now looks untenable. The Bulgaria bombing, followed by the arrest and conviction of a Hezbollah operative who was plotting a similar attack in Cyprus, has exposed the threat that the group's global network still poses in Europe. Meanwhile, the benefits of keeping communications open have disappeared. The U.K., for example, cut off all contacts with Hezbollah in 2010. Hezbollah helped force the collapse of the Lebanese government in March, and now the group is fighting alongside Syrian government troops in the civil war across the border.

Partly as a result of Hezbollah's actions in Syria, the conflict has begun to spill into Lebanon in earnest, pitting Sunnis against Alawites and Shiites. Europe should end the charade, list the entire group as the terrorist organization that it is, and shut down Hezbollah's funding and recruiting operations in Europe.